Moeriaan, a former Dutch Mennonite family, found in Alkmaar and particularly in the Zaan district of the province of North Holland. Simon Poulusz Moeriaan (died 1757), an oil miller, was a deacon of the Frisian congregation at Wormerveer. The best-known member of this family was Dirk Symonsz Moeriaan (1654-20 April 1728) of Zaandijk. He was a merchant, owner of an oil mill, shipowner, also owner of whaling vessels, and apparently a wealthy man. Besides all these businesses he still found time to devote to the Mennonite church. In 1679 he became a preacher, and later an elder of the Waterlander congregation of Koog aan de Zaan, serving for nearly 49 years until death, at first in the Waterlander, and after its merging (1690) with the Flemish in the united congregation of Koog-Zaandijk. Dirk Symonsz' influence extended beyond his home congregation into the Waterlander Conference. Being rather conservative, it was due to his influence that his congregation and also a number of other Waterlander churches in North Holland joined the Zonist conference. In 1722 he and Maarten Mol tried to bring about a complete union between the Zonists and the Lamists, but failed to achieve it. Dirk Symonsz was often invited to preach and baptize in other congregations. In 1699 he ordained Jan de Lanoy as an elder of the congregation at Hamburg. He had been trained for the ministry by E. A. van Dooregeest. His colleague Abraham Verduin commemorated his death in a funeral sermon, Heil in de Dood (published at Haarlem, n.d.).